Organization

Development Group for LWR Advanced technologyM.Ohsaka

Towards improvement of the safety performance and safe decommissioning of LWR, mechanism evaluation of the behavior of core and fuel material under normal operation and accident conditions are studied. Results are utilized for the improvement of models and severe accident management. Innovative concepts to improve safety performance are also considered.

Evaluation of radionuclide behavior under accident condition, fuel and material properties evaluation, improvement of evaluation method for activation amount of structural material are investigated. For research on radionuclide behavior under accident condition, chemical models are constructed for the rational evaluation of source term and the improving prediction capability of radionuclide distribution in Fukushima Daiichi Nuclear Power Station (1F). For relocation and propagation behavior of molten core, reactor vessel rupture behavior is evaluated. Results are reflected to vessel cooling measures and estimations of debris position in 1F, improvement of evaluation methods for radioactivity inventory in the decommissioning wastes, activation of structural materials and adhesion behavior of radioactive materials to the structural materials are studied. For the development of Accident Tolerant Fuel, fundamental data and technology are being prepared towards implementation of new fuels introduction into the present LWR.